Code walking pagetables but unware about huge pmds can simply call-split_huge_page_pmd(mm, pmd) where the pmd is the one returned by+split_huge_page_pmd(mm, pmd, addr) where the pmd is the one returned by pmd_offset. It's trivial to make the code transparent hugepage aware by just grepping for "pmd_offset" and adding split_huge_page_pmd where missing after pmd_offset returns the pmd. Thanks to the graceful@@ -299,7 +299,7 @@ diff --git a/mm/mremap.c b/mm/mremap.c return NULL;